This is a tough call. Mahomes is very mobile with great foot work and a rocket arm that is even doing basketball like moves as a QB flawlessly in some cases. Already threw for 50 TD's in his first season. Arm is up there with Marino, Favre, and Rogers. Watson is extremely slippery which is a rare description for certain guys abilities to run with the football in their hands. He mobility is as good as any QB in the entire NFL. He has very good passing abilities all over the field. Not nearly as good as Mahomes, but he has to do it under harder circumstances without much of a teacher and without much protection. Watson has a lot better mobility than Mahomes does as well. This isn't about who you think is better or will be better. Who is more exciting to watch?